A high-pressure gaseous hydrogen environment specimen hydrogen embrittlement testing device

Abstract

This invention discloses a hydrogen embrittlement testing device for high-pressure gaseous hydrogen environment samples, relating to the field of materials testing technology. It includes a high-pressure hydrogen tensile container, an elastic sealing container, and a compensation container. The high-pressure hydrogen tensile container is sealed and equipped with a tensile rod, one end of which penetrates the container and slides in a sealed manner. The elastic sealing container is located inside the high-pressure hydrogen tensile container and is connected to both the inner end of the tensile rod and the inner wall of the container. The compensation container is sealed and equipped with a sliding piston, which divides the compensation container into a liquid chamber and a gas chamber. The liquid chamber is connected to the elastic sealing container, and the gas chamber is connected to the high-pressure hydrogen tensile container. This device solves the problem that gas-liquid conversion mechanisms lack a real-time volume compensation mechanism when used in high-pressure gas environments, leading to pressure response lag and excessive fluctuation amplitude, thus failing to meet the requirements of precision testing.

Description

Technical Field

[0001] This invention relates to the field of materials testing technology, specifically to a hydrogen embrittlement testing device for samples in a high-pressure gaseous hydrogen environment. Background Technology

[0002] Materials subjected to prolonged operation in a high-pressure gaseous hydrogen environment will exhibit reduced plasticity, accelerated crack propagation, and low-stress failure, a phenomenon commonly known as environmental hydrogen embrittlement. To evaluate the hydrogen embrittlement resistance of materials, it is necessary to test their tensile, compressive, and fatigue mechanical properties in a high-pressure hydrogen environment. This inevitably involves the dynamic sealing of the high-pressure gas, which places extremely high demands on the sealing performance of the test container. Specifically, the sealed container must provide the tensile test conditions for the specimen (movement of the tensile rod), possess excellent sealing performance (dynamic sealing), and maintain a constant pressure within the sealed container for as long as possible (with an extremely low leakage rate (less than 1×10⁻⁷ Pa·m³ / s)).

[0003] Currently, most sealed containers used for testing the mechanical properties of materials in high-pressure gas environments employ gas dynamic sealing structures (such as the basic structure of the main body of the test equipment in Appendix A of GB / T34542.2-2018). Gas dynamic sealing structures cannot guarantee a very low leakage rate and have inherent drawbacks such as low reliability, high risk of gas leakage, and rapid pressure drop requiring timely gas replenishment. This is especially true when dealing with high-pressure hydrogen, as pressure fluctuations can exacerbate the flammability and explosiveness risks of hydrogen.

[0004] Liquid seals, due to the high surface tension and viscosity coefficient of liquids, offer simple dynamic sealing structures and excellent sealing performance, effectively improving pressure stability. By designing a reasonable gas-liquid conversion structure, dynamic seals stretched in a gas environment can be replaced with liquid dynamic seals that are stretched in a gas environment and slide in a liquid environment. This reduces the design and manufacturing difficulty of dynamic seals, lowers the risk of gas leakage, eliminates the need for gas replenishment, and improves system safety.

[0005] However, existing gas-liquid conversion structures lack a real-time volume compensation mechanism when used in high-pressure gas environments. The volume change caused by sample deformation needs to be transmitted through multiple mechanical stages, and the pressure response lag causes the fluctuation amplitude to exceed the standard, which cannot meet the requirements of precision testing.

[0006] Therefore, this application is hereby submitted. Summary of the Invention

[0007] The purpose of this invention is to provide a hydrogen embrittlement testing device for high-pressure gaseous hydrogen environment samples, which solves the problem that the gas-liquid conversion mechanism lacks a real-time volume compensation mechanism when used in a high-pressure gas environment, resulting in pressure response lag and excessive fluctuation amplitude, thus failing to meet the requirements of precision testing.

[0008] This invention is achieved through the following technical solution: A high-pressure gaseous hydrogen environment sample hydrogen embrittlement testing device includes: a high-pressure hydrogen tensile container, the high-pressure hydrogen tensile container being hermetically sealed, the high-pressure hydrogen tensile container having a tensile rod, one end of the tensile rod penetrating through the high-pressure hydrogen tensile container and slidingly engaging with it in a sealed manner, the tensile rod being used to pull a sample fixedly disposed within the high-pressure hydrogen tensile container; an elastic sealing container, the elastic sealing container being disposed within the high-pressure hydrogen tensile container and connected to the inner end of the tensile rod and the inner wall of the high-pressure hydrogen tensile container respectively, so that the volume of the elastic sealing container decreases as the tensile rod is pulled outward; and a compensation container, the compensation container being hermetically sealed, the compensation container having a piston slidingly disposed within it, so that the compensation container is divided into a liquid chamber and a gas chamber, the liquid chamber communicating with the elastic sealing container, and the gas chamber communicating with the high-pressure hydrogen tensile container.

[0009] In another preferred embodiment, the high-pressure hydrogen stretching container is provided with a support for setting up a sample, and the sample is fixedly connected to the support and the inner end of the stretching rod respectively.

[0010] In another preferred embodiment, the support includes a support member and multiple top supports; the top surface of the support member is used to support the sample and is fixedly connected to the sample; one end of the top support member along its length is fixedly connected to the top surface of the support member, and the other end is fixedly connected to the inner surface of the top wall of the high-pressure hydrogen stretching container.

[0011] In another preferred embodiment, a connecting disc is coaxially fixedly connected to the inner end of the tension rod; the elastic sealing container is cylindrical in shape and is coaxially fitted onto the outside of the tension rod; the bottom end of the elastic sealing container matches the shape of the connecting disc and is fixedly connected; the top end of the elastic sealing container is fixedly connected to the inner surface of the top wall of the high-pressure hydrogen tension container; the sample is clamped between the support and the connecting disc and is fixedly connected to both the support and the connecting disc.

[0012] In another preferred embodiment, the tension rod is coaxially sealed and slidably fitted with a fixing plate, the fixing plate being an elastic element, and the fixing plate being attached to and connected to the inner surface of the top wall of the high-pressure hydrogen tensioning container.

[0013] In another preferred embodiment, the liquid chamber is connected to a compensation liquid pipe, the other end of which passes through the top wall of the high-pressure hydrogen stretching container and the fixed plate in sequence, so as to communicate with the elastic sealing container.

[0014] In another preferred embodiment, the gas chamber is connected to the high-pressure hydrogen stretching container via a compensating gas pipe.

[0015] In another preferred embodiment, the gas chamber is provided with a compensating elastic sealing container, which is sandwiched between the piston and the cavity wall of the gas chamber; the end of the compensating gas pipe away from the high-pressure hydrogen stretching container passes through the cavity wall of the gas chamber and communicates with the compensating elastic sealing container.

[0016] In another preferred embodiment, both the resilient sealing container and the compensating resilient sealing container are bellows.

[0017] In another preferred embodiment, the high-pressure hydrogen stretching container is connected to a gas filling pipe, which is equipped with a gas valve; the liquid chamber is connected to a liquid filling pipe, which is equipped with a liquid valve.

[0018] The present invention, by adopting the above-mentioned technical solution, has the following positive effects compared with the prior art: This invention discloses a hydrogen embrittlement testing device for samples in a high-pressure gaseous hydrogen environment. It employs a high-pressure hydrogen stretching container to create a high-pressure hydrogen environment, with a stretching rod slidably mounted within it. The sample is placed inside and fixedly connected to the high-pressure hydrogen stretching container, and then pulled by the stretching rod to test the sample's resistance to hydrogen embrittlement under high-pressure hydrogen conditions. An elastic sealing container is positioned within the high-pressure hydrogen stretching container and connected to the stretching rod. When the stretching rod is pulled outward, it compresses the elastic sealing container, reducing its volume and filling it with liquid (hydraulic oil, etc.). Simultaneously, a compensation container with a piston separates a liquid chamber and a gas chamber, connecting them to the elastic sealing container and the high-pressure hydrogen stretching container, respectively. When the sample is pulled, the stretching rod simultaneously compresses the elastic sealing container, causing its volume to decrease synchronously. This forces the liquid inside into the liquid chamber, gradually increasing the pressure within the chamber and forcing the piston to... The device moves towards the gas chamber, compressing it and forcing hydrogen gas into the high-pressure hydrogen stretching container. As the volume of the elastically sealed container within the high-pressure hydrogen stretching container decreases (and the sample volume shrinks due to the stretching), the internal negative pressure increases. The hydrogen gas replenished from the gas chamber fills this volume change, maintaining a constant internal pressure within the high-pressure hydrogen stretching container. This ensures that the surrounding hydrogen pressure remains constant during sample stretching, guaranteeing consistent test conditions and accuracy. Furthermore, since the gas and liquid paths form closed systems, the resulting seal ensures pressure stability. Online gas and liquid addition is unnecessary during testing, shortening preparation time and avoiding the safety risks associated with online high-pressure gas injection. Through the combined effect of these features, this high-pressure gaseous hydrogen environment sample hydrogen embrittlement testing device effectively solves the problem of pressure response lag and excessive fluctuation amplitude caused by the lack of a real-time volume compensation mechanism in gas-liquid conversion mechanisms used in high-pressure gas environments, thus failing to meet the requirements for precision testing. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of a high-pressure gaseous hydrogen environment sample hydrogen embrittlement testing device provided by the present invention.

[0020] The attached diagram shows the markings and corresponding component names: 1-Sample; 10-High-pressure hydrogen tensile container; 11-Tensile rod; 111-Connecting disc; 112-Fixing disc; 12-Support; 121-Support component; 122-Top support component; 13-Gas filling pipe; 131-Gas valve; 20-Elastic sealing container; 30-Compensation container; 301-Liquid chamber; 302-Gas chamber; 31-Piston; 32-Compensation liquid pipe; 33-Compensation gas pipe; 34-Compensation elastic sealing container; 35-Liquid filling pipe; 351-Liquid valve. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", "front", "rear", "lateral", and "vertical" are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, and therefore should not be construed as a limitation of this invention.

[0023] It should be noted that the terms "horizontal" and "vertical" in this invention are used to describe approximate positional relationships, and not strictly "horizontal plane" or "vertical plane". Example

[0024] Please refer to Figure 1As shown, this embodiment provides a hydrogen embrittlement testing device for samples in a high-pressure gaseous hydrogen environment, comprising: a high-pressure hydrogen tensile container 10, the high-pressure hydrogen tensile container 10 being hermetically sealed, the high-pressure hydrogen tensile container 10 being provided with a tensile rod 11, one end of the tensile rod 11 penetrating through the high-pressure hydrogen tensile container 10 and being in a sealed sliding fit with the high-pressure hydrogen tensile container 10, the tensile rod 11 being used to pull out a sample 1 fixedly disposed in the high-pressure hydrogen tensile container 10; and a second device including an elastically sealed container 20, the elastically sealed container 20 being disposed in the high-pressure... The hydrogen stretching container 10 is connected to the inner end of the stretching rod 11 and the inner wall of the high-pressure hydrogen stretching container 10, so that the volume of the elastic sealing container 20 decreases as the stretching rod 11 is pulled outward; the third includes a compensation container 30, which is sealed, and a piston 31 is slidably provided in the compensation container 30, so that the compensation container 30 is divided into a liquid chamber 301 and a gas chamber 302. The liquid chamber 301 is connected to the elastic sealing container 20, and the gas chamber 302 is connected to the high-pressure hydrogen stretching container 10.

[0025] The high-pressure gaseous hydrogen environment sample hydrogen embrittlement testing device disclosed in this embodiment uses a high-pressure hydrogen stretching container 10 to create a high-pressure hydrogen environment. A stretching rod 11 is slidably installed within the container. The sample 1 is placed inside the high-pressure hydrogen stretching container 10 and fixedly connected to it. The sample 1 is then pulled by the stretching rod 11 to test its resistance to hydrogen embrittlement under high-pressure hydrogen conditions. An elastic sealing container 20 is installed within the high-pressure hydrogen stretching container 10 and connected to the stretching rod 11 so that the stretching rod 11 can compress the elastic sealing container when pulled outward. The container 20 is sealed to reduce its volume and filled with liquid (hydraulic oil, etc.). Simultaneously, a compensation container 30 is provided, within which a piston 31 is installed to separate a liquid chamber 301 and a gas chamber 302. The liquid chamber 301 and gas chamber 302 are connected to the elastically sealed container 20 and the high-pressure hydrogen stretching container 10, respectively. When the sample 1 is pulled, the stretching rod 11 simultaneously compresses the elastically sealed container 20, causing its volume to decrease synchronously, thereby forcing the liquid inside into the liquid chamber 301. The liquid forced into the liquid chamber 301... The pressure inside the liquid chamber 301 gradually increases, forcing the piston 31 to move towards the gas chamber 302, thus compressing the gas chamber 302 and forcing the hydrogen gas inside the gas chamber 302 into the high-pressure hydrogen stretching container 10. Due to the reduction in volume of the elastic sealing container 20 inside the high-pressure hydrogen stretching container 10 (and the reduction in volume of the sample 1 due to being pulled), the negative pressure inside increases. The hydrogen gas replenished from the gas chamber 302 fills this volume change, thus keeping the internal pressure of the high-pressure hydrogen stretching container 10 constant. This ensures that the hydrogen pressure in the surrounding environment remains constant during the pulling process of the sample 1, guaranteeing the measurement... The test environment remains unchanged, thus ensuring test accuracy. Furthermore, since the gas and liquid paths each form a closed system, the resulting seal ensures pressure stability. Online gas and liquid addition is unnecessary during testing, shortening test preparation time and avoiding the safety risks associated with online high-pressure gas injection. Through the synergy of these features, this high-pressure gaseous hydrogen environment sample hydrogen embrittlement testing device effectively solves the problem of the lack of a real-time volume compensation mechanism in gas-liquid conversion mechanisms used in high-pressure gas environments, which leads to pressure response lag and excessive fluctuation amplitude, failing to meet the requirements of precision testing.

[0026] In order to provide structural support and fixation for the sample 1, the high-pressure hydrogen stretching container 10 is provided with a bracket 12, which is used to set the sample 1. The sample 1 is fixedly connected to the bracket 12 and the inner end of the stretching rod 11 respectively.

[0027] It should be noted that the support 12 can fix the sample 1 by welding, clamping, threaded connection, etc., as long as the sample 1 can be fixed stably and firmly.

[0028] To further explain the specific structure of the support 12, the support 12 includes a support member 121 and multiple top supports 122; the top surface of the support member 121 is used to support the sample 1 and is fixedly connected to the sample 1; one end of the top support 122 in the longitudinal direction is fixedly connected to the top surface of the support member 121, and the other end is fixedly connected to the inner surface of the top wall of the high-pressure hydrogen stretching container 10.

[0029] With the above setup, the support member 121 is fixedly connected to the top wall of the high-pressure hydrogen tensile container 10 by the top support member 122. When the sample 1 is pulled out, the sample 1 applies an upward force to the support member 121. At this time, the top support member 122 will resist this force to ensure that the distance between the support member 121 and the top wall of the high-pressure hydrogen tensile container 10 remains unchanged, thereby ensuring the test accuracy.

[0030] To further explain the specific structure of the tension rod 11, a connecting disc 111 is coaxially fixedly connected to the inner end of the tension rod 11; the elastic sealing container 20 is cylindrical in shape and is coaxially fitted around the tension rod 11. The bottom end of the elastic sealing container 20 matches the shape of the connecting disc 111 and is fixedly connected, and the top end of the elastic sealing container 20 is fixedly connected to the inner surface of the top wall of the high-pressure hydrogen tension container 10; the sample 1 is clamped between the support member 121 and the connecting disc 111, and is fixedly connected to both the support member 121 and the connecting disc 111.

[0031] With the above configuration, by providing a connecting plate 111 at the inner end of the tension rod 11, the radial dimension of the inner end of the tension rod 11 is increased, thereby matching the bottom end of the elastic sealing container 20 and better compressing the elastic sealing container 20.

[0032] To further improve the sealing performance of the sliding fit between the tension rod 11 and the high-pressure hydrogen stretching container 10, a fixed plate 112 is coaxially and sealingly slidably fitted onto the tension rod 11. The fixed plate 112 is an elastic element, and it is attached and connected to the inner surface of the top wall of the high-pressure hydrogen stretching container 10.

[0033] To further explain the connection structure between the liquid chamber 301 and the elastic sealing container 20, the liquid chamber 301 is connected to a compensation liquid pipe 32, the other end of which passes through the top wall of the high-pressure hydrogen stretching container 10 and the fixed plate 112 in sequence, so as to connect with the elastic sealing container 20.

[0034] To further explain the connection structure between the gas chamber 302 and the high-pressure hydrogen stretching container 10, the gas chamber 302 is connected to the high-pressure hydrogen stretching container 10 through a compensating gas pipe 33.

[0035] To further improve the airtightness of the high-pressure hydrogen in the gas chamber 302, the gas chamber 302 is provided with a compensating elastic sealing container 34, which is sandwiched between the piston 31 and the cavity wall of the gas chamber 302; the end of the compensating gas pipe 33 away from the high-pressure hydrogen stretching container 10 passes through the cavity wall of the gas chamber 302 and communicates with the compensating elastic sealing container 34.

[0036] To further explain the specific structure of the elastic sealing container 20 and the compensating elastic sealing container 34, both the elastic sealing container 20 and the compensating elastic sealing container 34 are bellows.

[0037] In order to fill the device with the required amount of gas and liquid before testing, the high-pressure hydrogen stretching container 10 is connected to a gas filling pipe 13, which is equipped with a gas valve 131; the liquid chamber 301 is connected to a liquid filling pipe 35, which is equipped with a liquid valve 351.

[0038] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-pressure gaseous hydrogen environment sample hydrogen embrittlement testing device, characterized in that, include: A high-pressure hydrogen stretching container (10) is provided in a sealed manner. The high-pressure hydrogen stretching container (10) is provided with a stretching rod (11). One end of the stretching rod (11) passes through the high-pressure hydrogen stretching container (10) and is in a sealed sliding fit with the high-pressure hydrogen stretching container (10). The stretching rod (11) is used to pull out the sample fixedly disposed in the high-pressure hydrogen stretching container (10). An elastic sealing container (20) is disposed inside the high-pressure hydrogen stretching container (10) and is connected to the inner end of the stretching rod (11) and the inner wall of the high-pressure hydrogen stretching container (10) respectively, so that the volume of the elastic sealing container (20) decreases as the stretching rod (11) is pulled outward. The compensation container (30) is sealed and a piston (31) is slidably provided inside the compensation container (30) to divide the compensation container (30) into a liquid chamber (301) and a gas chamber (302). The liquid chamber (301) is connected to the elastic sealing container (20) and the gas chamber (302) is connected to the high-pressure hydrogen stretching container (10).

2. The high-pressure gaseous hydrogen environment sample hydrogen embrittlement testing device according to claim 1, characterized in that, The high-pressure hydrogen stretching container (10) is provided with a support (12), which is used to set the sample. The sample is fixedly connected to the support (12) and the inner end of the stretching rod (11).

3. The high-pressure gaseous hydrogen environment sample hydrogen embrittlement testing device according to claim 2, characterized in that, The bracket (12) includes a support member (121) and multiple top support members (122). The top surface of the support member (121) is used to support the sample and is fixedly connected to the sample. One end of the top support (122) along its length is fixedly connected to the top surface of the support (121), and the other end is fixedly connected to the inner surface of the top wall of the high-pressure hydrogen stretching container (10).

4. The high-pressure gaseous hydrogen environment sample hydrogen embrittlement testing device according to claim 3, characterized in that, The inner end of the tension rod (11) is coaxially fixedly connected to the connecting plate (111). The elastic sealing container (20) is cylindrical in shape. The elastic sealing container (20) is coaxially fitted outside the tension rod (11). The bottom end of the elastic sealing container (20) matches the shape of the connecting plate (111) and is fixedly connected. The top end of the elastic sealing container (20) is fixedly connected to the inner surface of the top wall of the high-pressure hydrogen tension container (10). The sample is clamped between the support (121) and the connecting plate (111), and is fixedly connected to the support (121) and the connecting plate (111) respectively.

5. The high-pressure gaseous hydrogen environment sample hydrogen embrittlement testing device according to claim 4, characterized in that, The tension rod (11) is coaxially sealed and slidably fitted with a fixed plate (112). The fixed plate (112) is an elastic element and is attached and connected to the inner surface of the top wall of the high-pressure hydrogen tension container (10).

6. The high-pressure gaseous hydrogen environment sample hydrogen embrittlement testing device according to claim 5, characterized in that, The liquid chamber (301) is connected to a compensation liquid pipe (32), and the other end of the compensation liquid pipe (32) passes through the top wall of the high-pressure hydrogen stretching container (10) and the fixed plate (112) in sequence, so as to communicate with the elastic sealing container (20).

7. The high-pressure gaseous hydrogen environment sample hydrogen embrittlement testing device according to claim 6, characterized in that, The gas chamber (302) is connected to the high-pressure hydrogen stretching container (10) through a compensating gas pipe (33).

8. The high-pressure gaseous hydrogen environment sample hydrogen embrittlement testing device according to claim 7, characterized in that, The air chamber (302) is provided with a compensating elastic sealing container (34), which is sandwiched between the piston (31) and the cavity wall of the air chamber (302); The end of the compensating gas pipe (33) away from the high-pressure hydrogen stretching container (10) passes through the cavity wall of the gas chamber (302) and is connected to the compensating elastic sealing container (34).

9. The high-pressure gaseous hydrogen environment sample hydrogen embrittlement testing device according to claim 8, characterized in that, Both the elastic sealing container (20) and the compensating elastic sealing container (34) are bellows.

10. The high-pressure gaseous hydrogen environment sample hydrogen embrittlement testing device according to claim 1, characterized in that, The high-pressure hydrogen stretching container (10) is connected to a gas filling pipe (13), and the gas filling pipe (13) is equipped with a gas valve (131). The liquid chamber (301) is connected to a liquid filling pipe (35), and the liquid filling pipe (35) is equipped with a liquid valve (351).

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